Method and apparatus for allocating discovery resource pools in a wireless communication system

ABSTRACT

A method and apparatus for allocating discovery resource pools are disclosed. The method includes the WCN receiving a Discovery Request message from a UE. The method further includes the WCN transmitting a Discovery Response message to the UE, wherein the Discovery Response message includes information to indicate at least a discovery resource pool for the UE to use.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/951,132 filed on Mar. 11, 2014, the entiredisclosure of which is incorporated herein by reference.

FIELD

This disclosure generally relates to wireless communication networks,and more particularly, to a method and apparatus for allocatingdiscovery resource pools in a wireless communication system.

BACKGROUND

With the rapid rise in demand for communication of large amounts of datato and from mobile communication devices, traditional mobile voicecommunication networks are evolving into networks that communicate withInternet Protocol (IP) data packets. Such IP data packet communicationcan provide users of mobile communication devices with voice over IP,multimedia, multicast and on-demand communication services.

An exemplary network structure for which standardization is currentlytaking place is an Evolved Universal Terrestrial Radio Access Network(E-UTRAN). The E-UTRAN system can provide high data throughput in orderto realize the above-noted voice over IP and multimedia services. TheE-UTRAN system's standardization work is currently being performed bythe 3GPP standards organization. Accordingly, changes to the currentbody of 3GPP standard are currently being submitted and considered toevolve and finalize the 3GPP standard.

SUMMARY

A method and apparatus for allocating discovery resource pools aredisclosed. The method includes the wireless communication network (WCN)receiving a Discovery Request message from a UE. The method furtherincludes the WCN transmitting a Discovery Response message to the UE,wherein the Discovery Response message includes information to indicateat least a discovery resource pool for the UE to use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram of a wireless communication system according toone exemplary embodiment.

FIG. 2 is a block diagram of a transmitter system (also known as accessnetwork) and a receiver system (also known as user equipment or UE)according to one exemplary embodiment.

FIG. 3 is a functional block diagram of a communication system accordingto one exemplary embodiment.

FIG. 4 is a functional block diagram of the program code of FIG. 3according to one exemplary embodiment.

FIG. 5 is a reproduction of FIG. 2 of 3GPP R2-140474.

FIG. 6 is a reproduction of FIG. 5.3.1-1 of 3GPP S2-140520.

FIG. 7 is a reproduction of FIG. 5.3.2.1-1 of 3GPP S2-140520.

FIG. 8 is a reproduction of FIG. 5.3.2.3-1 of 3GPP S2-140520.

FIG. 9 is a flow chart according to one exemplary embodiment.

FIG. 10 is a flow chart according to one exemplary embodiment.

DETAILED DESCRIPTION

The exemplary wireless communication systems and devices described belowemploy a wireless communication system, supporting a broadcast service.Wireless communication systems are widely deployed to provide varioustypes of communication such as voice, data, and so on. These systems maybe based on code division multiple access (CDMA), time division multipleaccess (TDMA), orthogonal frequency division multiple access (OFDMA),3GPP LTE (Long Term Evolution) wireless access, 3GPP LTE-A orLTE-Advanced (Long Term Evolution Advanced), 3GPP2 UMB (Ultra MobileBroadband), WiMax, or some other modulation techniques.

In particular, the exemplary wireless communication systems devicesdescribed below may be designed to support one or more standards such asthe standard offered by a consortium named “3rd Generation PartnershipProject” referred to herein as 3GPP, including RAN1-73 minutes report;R2-134287, “Type 2B resource allocation for D2D discovery”, IntelCorporation; RAN2#85 minutes report; R2-140474, “Open Issues of D2DDiscovery”, Qualcomm Incorporated; R2-140692, “Resource allocation forD2D discovery”, ZTE; S2-140520, “Direct discovery procedures”, QualcommIncorporated; R1-140337, “Resource Allocation and UE Behavior for D2DDiscovery”, LG Electronics. The standards and documents listed above arehereby expressly incorporated by reference in their entirety.

FIG. 1 shows a multiple access wireless communication system accordingto one embodiment of the invention. An access network 100 (AN) includesmultiple antenna groups, one including 104 and 106, another including108 and 110, and an additional including 112 and 114. In FIG. 1, onlytwo antennas are shown for each antenna group, however, more or fewerantennas may be utilized for each antenna group. Access terminal 116(AT) is in communication with antennas 112 and 114, where antennas 112and 114 transmit information to access terminal 116 over forward link120 and receive information from access terminal 116 over reverse link118. Access terminal (AT) 122 is in communication with antennas 106 and108, where antennas 106 and 108 transmit information to access terminal(AT) 122 over forward link 126 and receive information from accessterminal (AT) 122 over reverse link 124. In a FDD system, communicationlinks 118, 120, 124 and 126 may use different frequency forcommunication. For example, forward link 120 may use a differentfrequency then that used by reverse link 118.

Each group of antennas and/or the area in which they are designed tocommunicate is often referred to as a sector of the access network. Inthe embodiment, antenna groups each are designed to communicate toaccess terminals in a sector of the areas covered by access network 100.

In communication over forward links 120 and 126, the transmittingantennas of access network 100 may utilize beamforming in order toimprove the signal-to-noise ratio of forward links for the differentaccess terminals 116 and 122. Also, an access network using beamformingto transmit to access terminals scattered randomly through its coveragecauses less interference to access terminals in neighboring cells thanan access network transmitting through a single antenna to all itsaccess terminals.

An access network (AN) may be a fixed station or base station used forcommunicating with the terminals and may also be referred to as anaccess point, a Node B, a base station, an enhanced base station, anevolved Node B (eNB), or some other terminology. An access terminal (AT)may also be called user equipment (UE), a wireless communication device,terminal, access terminal or some other terminology.

FIG. 2 is a simplified block diagram of an embodiment of a transmittersystem 210 (also known as the access network) and a receiver system 250(also known as access terminal (AT) or user equipment (UE)) in a MIMOsystem 200. At the transmitter system 210, traffic data for a number ofdata streams is provided from a data source 212 to a transmit (TX) dataprocessor 214.

In one embodiment, each data stream is transmitted over a respectivetransmit antenna. TX data processor 214 formats, codes, and interleavesthe traffic data for each data stream based on a particular codingscheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by processor 230.

The modulation symbols for all data streams are then provided to a TXMIMO processor 220, which may further process the modulation symbols(e.g., for OFDM). TX MIMO processor 220 then provides N_(T) modulationsymbol streams to N_(T) transmitters (TMTR) 222 a through 222 t. Incertain embodiments, TX MIMO processor 220 applies beamforming weightsto the symbols of the data streams and to the antenna from which thesymbol is being transmitted.

Each transmitter 222 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transmitters 222 a through 222 t are thentransmitted from N_(T) antennas 224 a through 224 t, respectively.

At receiver system 250, the transmitted modulated signals are receivedby N_(R) antennas 252 a through 252 r and the received signal from eachantenna 252 is provided to a respective receiver (RCVR) 254 a through254 r. Each receiver 254 conditions (e.g., filters, amplifies, anddownconverts) a respective received signal, digitizes the conditionedsignal to provide samples, and further processes the samples to providea corresponding “received” symbol stream.

An RX data processor 260 then receives and processes the N_(R) receivedsymbol streams from N_(R) receivers 254 based on a particular receiverprocessing technique to provide N_(T) “detected” symbol streams. The RXdata processor 260 then demodulates, deinterleaves, and decodes eachdetected symbol stream to recover the traffic data for the data stream.The processing by RX data processor 260 is complementary to thatperformed by TX MIMO processor 220 and TX data processor 214 attransmitter system 210.

A processor 270 periodically determines which pre-coding matrix to use(discussed below). Processor 270 formulates a reverse link messagecomprising a matrix index portion and a rank value portion.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 238, whichalso receives traffic data for a number of data streams from a datasource 236, modulated by a modulator 280, conditioned by transmitters254 a through 254 r, and transmitted back to transmitter system 210.

At transmitter system 210, the modulated signals from receiver system250 are received by antennas 224, conditioned by receivers 222,demodulated by a demodulator 240, and processed by a RX data processor242 to extract the reserve link message transmitted by the receiversystem 250. Processor 230 then determines which pre-coding matrix to usefor determining the beamforming weights then processes the extractedmessage.

Turning to FIG. 3, this figure shows an alternative simplifiedfunctional block diagram of a communication device according to oneembodiment of the invention. As shown in FIG. 3, the communicationdevice 300 in a wireless communication system can be utilized forrealizing the UEs (or ATs) 116 and 122 in FIG. 1, and the wirelesscommunications system is preferably the LTE system. The communicationdevice 300 may include an input device 302, an output device 304, acontrol circuit 306, a central processing unit (CPU) 308, a memory 310,a program code 312, and a transceiver 314. The control circuit 306executes the program code 312 in the memory 310 through the CPU 308,thereby controlling an operation of the communications device 300. Thecommunications device 300 can receive signals input by a user throughthe input device 302, such as a keyboard or keypad, and can outputimages and sounds through the output device 304, such as a monitor orspeakers. The transceiver 314 is used to receive and transmit wirelesssignals, delivering received signals to the control circuit 306, andoutputting signals generated by the control circuit 306 wirelessly.

FIG. 4 is a simplified block diagram of the program code 312 shown inFIG. 3 in accordance with one embodiment of the invention. In thisembodiment, the program code 312 includes an application layer 400, aLayer 3 portion 402, and a Layer 2 portion 404, and is coupled to aLayer 1 portion 406. The Layer 3 portion 402 generally performs radioresource control. The Layer 2 portion 404 generally performs linkcontrol. The Layer 1 portion 406 generally performs physicalconnections.

For LTE or LTE-A systems, the Layer 2 portion may include a Radio LinkControl (RLC) layer and a Medium Access Control (MAC) layer. The Layer 3portion may include a Radio Resource Control (RRC) layer.

According to 3GPP RAN1-73 minutes report, it was agreed there will bethree kinds of resource allocation methods as follows:

Agreement

At least the following two types of discovery procedure are defined forthe purpose of terminology definition for use in furtherdiscussions/studies (note that these definitions are intended only toaid clarity and not to limit the scope of the study):

-   -   Type 1: a discovery procedure where resources for discovery        signal transmission are allocated on a non UE specific basis        -   Note: Resources can be for all UEs or group of UEs    -   Type 2: a discovery procedure where resources for discovery        signal transmission are allocated on a per UE specific basis    -   Type 2A: Resources are allocated for each specific transmission        instance of discovery signals    -   Type 2B: Resources are semi-persistently allocated for discovery        signal transmission

In general, Type 1 discovery resource is contention-based resource,while Type 2A and 2B discovery resources are central controlled (ordedicated) resources.

In addition, 3GPP R2-134287 describes some use cases can benefit fromtype 2B resources as follows:

Advantage of Type 2B Resource Allocation

There are several cases that we can get benefit by using Type 2Bresource allocation.

-   -   RRC_CONNECTED UEs: the signalling overhead for resource        allocation is considered as comparable to Type 1 because SPS        based scheduling requires only when resource is        activated/released. However, the main concern on Type 2B        resource allocation is the signalling overhead due to RRC        connection management. In Type 2B, the UE needs to establish RRC        connection to request UE specific discovery resource and may        cause HO procedure if the UE is moving and kept in RRC_CONNECTED        mode for discovery operation. However, if the UE happens to be        in RRC_CONNECTED mode for normal LTE data service, there is no        additional signalling overhead for discovery operation.    -   Public safety support: although there is no requirement to        prioritize a certain discovery service, it may be good to        support the option providing better performance for the case        where low latency and high reliability is required for        discovery. The main concern of Type 1 resource allocation is        collision between the UEs selecting the same discovery resource.        Although the collision probability can be controlled and        mitigated with various schemes, collision cannot be fully        resolved. Especially, in emergency situation in Public safety        scenario, collision may be more increased if a lot of UEs tries        to perform discovery. In this case, if the eNB can allocate UE        specific dedicated resource for discovery, the discovery signal        can be detected by other UEs without collision. Consequently, it        reduces discovery time and power consumption.    -   Stationary UEs: as mentioned in [1], it is expected that some        D2D UEs are used for the commercial purpose e.g. stores,        restaurants, etc. In this case, these UEs are stationary and        thus, are not subject to handover to neighbouring cells. In        addition, depending on business model, the discovery of these        UEs can be more prioritized. In this case, Type 2B resource        allocation is more beneficial than Type 1 because collision-free        discovery resource can provide low latency and high reliability        without signalling overhead.

Based on the above observations, Type 2B resource allocation providesbenefit without increasing signalling overhead significantly. Since RAN2has agreed that the transmission and reception of discovery signal issupported in RRC_IDLE mode and RRC_CONNECTED mode, Type 1 should bebaseline as proposed in [2]. However, on top of Type 1, Type 2B shouldbe supported considering the useful cases identified above.

Proposal 1:

RAN2 is asked to support Type 2B resource allocation method for D2Ddiscovery in addition to Type 1.

Furthermore, 3GPP RAN2#85 minutes report addresses some agreements onD2D discovery service as follows:

Agreements

For in-coverage discovery . . . .

-   -   1 the eNB may provide in SIB . . . .        -   a) a radio resource pool for discovery reception of Type 2B        -   b) a radio resource pool for discovery transmission and            reception in case of Type 1 (FFS for inter-cell discovery)

    -   2 In case of Type 1, a UE autonomously selects radio resources        from that indicated transmissions resource pool for discovery        signal transmission.

    -   

    -   3 In case of Type 2B, only an RRC Connected UE may request        resources for transmission of D2D discovery messages from the        eNB via RRC and the eNB assigns these resource via RRC. As        baseline, UE releases the transmission resources the latest when        the UE enters IDLE or when the eNB withdraws the resource by RRC        signalling.

    -   6 Receiving UEs monitor both Type 1 and Type 2B discovery        resources

    -   

Specifically, 3GPP R2-140474 proposes using D2D discovery resourcerequest/response messages to request and allocate Type 2 discoveryresource in FIG. 2 entitled “D2D Resource request and response messagefor Type 2”, which has been reproduced as FIG. 5.

3GPP R2-140692 further recommends the following:

Proposal 3:

It is recommended that Type 1 procedure is used for IDLE state UEs whileType 2 procedure is applied for CONNECTED state UEs.

In addition, 3GPP S2-140520 defines ProSe Application ID and ProSeApplication Code for use in discovery as follows:

4.6.2 Identifiers for Direct Discovery 4.6.2.1 ProSe Application ID

The ProSe Application ID is an identity used for direct discovery,identifying application related information for the ProSe enabled UE.Each ProSe Application ID is globally unique and unambiguouslyidentifies a service across the 3GPP PLMNs.

For open discovery, the ProSe Application ID is called Public ProSeApplication ID. The Public ProSe Application ID can be PLMN-specific orcountry specific or global.

Each Public ProSe Application ID is composed of the following parts:

-   -   a. ProSe Application ID Name is described in its entirety by a        data structure that could be a tree data structure characterized        by different levels e.g., broad-level business category        (Level0)/business sub-category (Level1)/business name        (Level2)/shop ID (Level3). For the purpose of presentation, a        ProSe Application ID Name is usually displayed as a string of        labels in which the labels represent hierarchical levels.    -   b. ProSe Application ID Operator Identifier that corresponds to        the PLMN id that assigned the ProSe Application ID Name    -   NOTE: If the public ProSe Application ID is country specific        then the Mobile Network Code (MNC) of the ProSe Application ID        Operator Identifier is wild carded. If global, both the MCC and        MNC are wild carded.

In case of open discovery:

-   -   when the “announcing” UE wants to indicate to the ProSe Function        what is interested to announce, in order to be assigned a ProSe        Application Code it contains in the discovery request a Public        ProSe Application ID that indicates its interest    -   when the “monitoring” UE wants to indicate to the ProSe Function        what to monitor, it contains in the discovery request the full        or a subset of the public ProSe Application ID e.g. it can        contain 2 out of the n levels of the full Public ProSe        Application ID

NOTE: The ProSe Application ID Name tree data structure is not expectedto change often.

4.6.2.2 ProSe Application Code

The ProSe Application Code is contained in the message that is actuallytransmitted “over the air” (on PC5) by a UE engaged in the ProSe directdiscovery procedure.

Each ProSe Application Code is composed of the following parts:

-   -   a. A temporary identity that corresponds to the ProSe        Application ID Name. Given the tree structure associated with        public ProSe Application ID, each is associated with a different        temporary identity that is built appending a new piece of        identifier (specific to that node) to the identifier inherited        by the predecessor node: this allows partial matching at the UE        side using a mask, making more effective and flexible the        filtering of the received temporary identity in a monitoring UE.    -   b. The PLMN id that assigned the ProSe Code, i.e. Mobile Country        Code (MCC) and Mobile Network Code (MNC)    -   c. The ProSe Function Identifier of the Prose Function that has        assigned the ProSe Code.    -   Editor's Note: The need for ProSe Function Identifier as part of        the ProSe Application Code is FFS.    -   NOTE: In this release of the specification the ProSe Application        Code is always assigned by a ProSe Function in HPLMN.

A ProSe Application Code is allocated per “announcing” UE and perapplication and has an associated validity timer that runs both in theProSe Function and in the UE.

The ProSe Function may decide at any time to replace a previouslyallocated ProSe Application Code providing the UE with a new ProSeApplication Code, where the temporary UE specific identifier is changed.Replacing a ProSe Code resets the corresponding validity timer both inthe ProSe Function and in the UE.

Editor's Note: Each sub-section specifies a new identifier required forProSe.

Also, 3GPP S2-140520 specifies the procedures for D2D discovery asfollows:

5.3.1 Overall Procedure for Direct Discovery

[FIG. 5.3.1-1 of 3GPP S2-140520 has been Reproduced as FIG. 6]

-   -   1. Service authorisation for ProSe direct services is performed        for direct discovery as defined in clause 5.2, and 4.5.1.        If the UE is authorised to announce:    -   2a. When the UE is triggered to announce then it sends a        discovery request for announcing to the ProSe Function in HPLMN        as defined in clauses 5.3.2.1 and 5.3.2.2.    -   3a. If the request is successful and is provided with ProSe        Application Code then it starts announcing on PC5 interface.    -   NOTE: More details on the Access Stratum protocol of this step        are provided in RAN specifications.

If the UE is authorised to monitor:

-   -   2b. When the UE is triggered to monitor, it sends a discovery        request for monitoring to the ProSe Function as defined in        clauses 5.3.2.3 and 5.3.2.4.    -   3b. If the request is successful and the UE is provided with a        Discovery Filter consisting of ProSe Application Code(s) or        mask(s) starts monitoring for ProSe Application Codes on PC5        interface.

NOTE: More details on the Access Stratum protocol of this step areprovided in RAN specifications.

-   -   4b. When the UE detects that one or more ProSe Application        Code(s) that match the filter, it reports the ProSe Application        Code(s) to the ProSe Function as defined in clause 5.3.3.

    -   

5.3.2.1 Announce Request (Non-Roaming)

[FIG. 5.3.2.1-1 of 3GPP S2-140520 has been Reproduced as FIG. 7]

-   -   0. The UE is configured with offline mechanisms with the tree        data structure of the ProSe Application IDs corresponding to        HPLMN. This step is performed using mechanisms out of scope of        3GPP.    -   1. If the UE is authorised to announce in HPLMN and is triggered        to announce, it shall establish a secure connection and it shall        send a Discovery Request (ProSe Application ID, UE Identity,        announce command, application identity) message for announcing.        The ProSe Application ID indicates what the UE is interested to        announce. The UE Identity identifies the UE subscription and can        be the e.g. IMSI or MSISDN. The application identity represents        a unique identifier of the UE application that has triggered the        Discovery Request. This request is always sent to the ProSe        Function in HPLMN.        -   NOTE: The application identity uniquely identifies the            application itself. All common mobile operating systems have            namespaces that identify the applications within this            operating system.    -   Editor's Note: It is up to stage-3 to determine whether for the        application identity the operating specific identity would        suffice or a namespace needs to be defined by 3GPP that will be        common across all operating systems.    -   Editor's Note: The mechanism to establish a secure connection        between the UE and the ProSe Function will be defined by SA WG3.    -   2. If there is no associated UE context, the ProSe Function        shall check with HSS the authorisation for discovery and create        a new context for this UE that contains the subscription        parameters for this UE.    -   3. If the Discovery Request is authorised, then the ProSe        Function shall respond with a Discovery Response (ProSe        Application Code, validity timer) message. ProSe Application        Code is provided by the ProSe Function and corresponds to the        ProSe Application ID that was contained in the Discovery        Request. The validity timer indicates for how long this ProSe        Application Code is going to be valid. The UE will be authorised        to announce this ProSe Application Code for the duration of        validity timer and if it does not change its registered or        equivalent PLMN. When the validity timer expires or the UE        changes its registered or equivalent PLMN the UE may need to        request a new ProSe Application Code.    -   4. The UE may start announcing the provided ProSe Application        Code in HPLMN, using the radio resources authorised and        configured by E-UTRAN to be used for ProSe.    -   Editor's Note: The mechanism to protect the discovery message        will be defined by SA WG3.    -   Editor's Note: The correct representation of radio resource        allocation from E-UTRAN needs to be revised.

5.3.2.3 Monitor Request (Non-Roaming)

[FIG. 5.3.2.3-1 of 3GPP S2-140520 has been Reproduced as FIG. 8]

-   -   0. The UE is configured using offline mechanisms with the tree        data structure of the ProSe Application IDs corresponding to        PLMNs the UE is authorised to monitor. This step is performed        using mechanisms out of scope of 3GPP.    -   1. If the UE is authorised to monitor in at least one PLMN and        is interested to monitor certain ProSe Application ID(s), it        shall establish a secure connection and shall send a Discovery        Request (ProSe Application ID(s), UE Identity, monitor command,        application identity) message for monitoring. The ProSe        Application ID(s) indicate what the UE is interested to monitor        and they consist a subset of the tree data structure of the        PLMN. The UE Identity identifies the UE subscription and can be        the e.g. IMSI or MSISDN. The application identity represents a        unique identifier of the application that has triggered the        discovery request. This request is always sent to the ProSe        Function in HPLMN.        -   NOTE 1: The Application Identity Uniquely Identifies the            Application Itself. All Common mobile operating systems have            namespaces that identify the applications within this            operating system.    -   Editor's Note: It is up to stage-3 to determine whether for the        application identity the operating specific identity would        suffice or a namespace needs to be defined by 3GPP that will be        common across all operating systems.    -   Editor's Note: The mechanism to establish a secure connection        between the UE and the ProSe Function will be defined by SA WG3.    -   2. If there is no associated UE context, the ProSe Function        shall check with HSS the authorisation for discovery and create        a new context for this UE that contains the subscription        parameters for this UE. The authorisation information also        contains the PLMNs that this UE is allowed to perform discovery.

If the Discovery Request is authorised and the ProSe Application ID sentby the UE in step 1 indicates another local PLMN in the same countrythen steps 3-6 are executed, otherwise steps 5-6 only:

-   -   3. The ProSe Function in HPLMN shall contact other local PLMNs        in the same country in order to resolve the ProSe Application ID        Name(s) to mask(s) that corresponds to this ProSe Application ID        Name. The request shall also include the UE identity information        e.g. IMSI or MSISDN in order to allow the ProSe Function in        local PLMN to perform charging.    -   4. The ProSe Function of the local PLMN returns the related        mask(s) and the corresponding TTL for each.    -   5. The ProSe Function in the HPLMN shall respond with a        Discovery Response (Discovery Filter(s), Filter id) message. The        Discovery Filter(s) consists of the ProSe Application mask(s).        The Discovery Filter(s) include the TTL(s). The TTL(s) in the        Discovery Filter(s) indicates for how long the Discovery        Filter(s) is going to be valid.        -   NOTE 2: The UE can randomize the request for assignment of            new Discovery Filter in order to guard against a peak of            Discovery Requests when the TTL expires.    -   6. The UE may start monitoring using the Discovery Filter(s) in        the radio resources that are authorized and configured by the        PLMN(s) to be used for ProSe.        Editor's Note: The correct representation of radio resource        allocation from E-UTRAN needs to be revised.

U.S. Provisional Patent Application Ser. No. 61/731,712 discloses aconcept of separate sets of discovery resources for different use cases;and transmitting and receiving UEs may determine which set of resourcesto transmit/receive discovery signaling based on user's setting. U.S.Provisional Patent Application Ser. No. 61/731,712 is herebyincorporated by reference in its entirety.

In addition, 3GPP R1-140337 discusses whether the type 2 resourceallocation information should be delivered to the receiver UEs asfollows:

3.2. Type 2 Discovery

[ . . . ]

The potential drawback of Type 2B discovery is that it requires moresignaling overhead and UE power consumption because a UE needs to be inthe RRC_Connected state to be provided with the per-UE resourceconfiguration from the network. However, it is possible to apply Type 2Bdiscovery in RRC_Idle state depending on the details of high layerprocedure; network provides discovery resource in RRC_Connected stateand the UE applies the provided resource in RRC_Idle state [2]. In thiscase, the system can take advantage of the power and signal efficiencyof RRC_Idle mode while exploiting the collision-free nature of Type 2Bdiscovery.

Triggering Type 2A discovery can be similar to the aperiodic SRSmechanism, but its usefulness needs to be considered further inconsideration of the required signaling overhead.

One consideration point in Type 2 discovery is whether the resourceallocation information is delivered to the receiver UEs. If delivered,the receiver UE can limit the discovery message search so that the falsedetection probability is reduced and UE battery can be saved. If higherlayer signaling is used for this purpose, it can be interpreted as theindication of the candidates for Type 2 discovery signal transmissions.If physical layer signaling is used, it can be interpreted as theindication of the actual Type 2 discovery signal transmissions. If noinformation is delivered to the receiver UEs, the reception procedurewill be the same as that in Type 1 discovery case.

Type 1 resource pool could be considered a common resource pool becausethe pool is shared by all UEs. Type 2B resource pool is a type ofdedicated resource pool because the resources are allocated by the eNBfor specific UEs.

For a common resource pool, Announcing UEs autonomously select theresources from the pool before transmission of discovery signaling. Itis very likely that a resource is chosen by two or more Announcing UEs.This collision would degrade the D2D discovery performance. But fordedicated resource pool, it is contention free and thus provides betterperformance. It seems better to specify a rule for Announcing UEs todetermine which pool to use. Otherwise, most UEs may request fordedicated resources, which would easily cause resource congestion.

3GPP R2-140692 recommends that idle mode UEs use the common resourcepool and connected mode UEs use the dedicated resource pool. This issimple. But, it would be more attractive to operators to allocate thediscovery resources based on the user subscription or the service forwhich the discovery is to be used by a UE so that operators could chargedifferently for different user subscriptions or services. This shouldalso be quite fair from user's point of view because a better servicedeserves more money.

In general, there are two directions to realize the above concept:

a. UE Based

It is assumed that there exists subscription information in a UE, whichindicates whether the UE is allowed to use dedicated resources. If it isallowed, the UE sends a message to the network (NW) for requesting thededicated resources. Otherwise, the UE uses common resources fordiscovery transmission. In this situation, a Monitoring UE needs tomonitor both resource pools.

b. NW Based

According to 3GPP S2-140520, an Announcing UE sends a Discovery Requestto NW when it is triggered to announce. When receiving the DiscoveryRequest from the UE, the NW could determine which resource pool shouldbe used by this UE based on the user subscription or the service forwhich the discovery is to be used by the UE. For instance, the NW mayfetch the user subscription according to the UE identity included in theDiscovery Request and may know the service according to ProSeApplication ID included in the Discovery Request. The NW could thenindicate the resource pool to the Announcing UE in a Discovery Response.For Monitoring UEs, the NW could similarly determine the resource poolbased on the ProSe Application ID included in the Discovery Request.With the instruction received during the Discovery Request Procedure,each UE would know whether it needs to request dedicated discoveryresource from the eNB.

Furthermore, it would be beneficial for the eNB to indicate in thesystem information if dedicated resources are available so that anAnnouncing UE could avoid sending a message to requesting dedicatedresources. This not only can save UE power, but also can reducesignaling.

FIG. 9 is a flow chart 900 in accordance with one exemplary embodimentfrom the perspective of a wireless communication network (WCN). In step905, the WCN receives a Discovery Request message from a user equipment(UE). In one embodiment, the Discovery Request message could include atleast a ProSe Application ID or at least a part or a subset of a ProSeApplication ID.

In step 910, the WCN transmits a Discovery Response message to the UE,wherein the Discovery Response message includes information to indicateat least a discovery resource pool for the UE to use. In addition, theDiscovery Response message could include a ProSe Application Code and/ora discovery filter. Furthermore, the ProSe Application Code could becontained in a discovery signal transmitted “over the air” by the UE.

In step 915, the WCN receives a D2D Discovery Resource Request messagefrom the UE if the information included in the Discovery Responsemessage indicates at least a dedicated discovery resource pool for theUE to use. In step 920, the WCN transmits a D2D Discovery ResourceResponse message to the UE in response to reception of the D2D DiscoveryResource Request message, wherein the D2D Discovery Resource Responsemessage includes a configuration of dedicated discovery resource for theUE to use. Furthermore, the WCN indicates if dedicated discoveryresources are available in a system information message.

In one embodiment, a configuration of the common discovery resource pooland/or a configuration of the dedicated discovery resource pool areincluded in a system information message.

Referring back to FIGS. 3 and 4, the device 300 includes a program code312 stored in memory 310. The CPU 308 could execute program code 312 theenable the WCN (i) to receive a Discovery Request message from a UE, and(ii) to transmit a Discovery Response message to the UE, wherein theDiscovery Response message includes information to indicate at least adiscovery resource pool for the UE to use. In addition, the CPU 308 canexecute the program code 312 to perform all of the above-describedactions and steps or others described herein.

FIG. 10 is a flow chart 1000 in accordance with one exemplary embodimentfrom the perspective of a UE. In step 1005, the UE transmits a DiscoveryRequest message to the WCN. In one embodiment, the Discovery Requestmessage could include at least a ProSe Application ID or at least a partor a subset of a ProSe Application ID. Furthermore, the ProSeApplication ID could be an identity used for direct discovery and foridentifying a service.

In step 1010, the UE receives a Discovery Response message from the WCN,wherein the Discovery Response message includes information to indicateat least a discovery resource pool for the UE to use. In addition, theDiscovery Response message could include a ProSe Application Code and/ora discovery filter. Furthermore, the ProSe Application Code could becontained in a discovery signal transmitted “over the air” by the UE.

In step 1015, the UE transmits a D2D Discovery Resource Request messageto the WCN if the information included in the Discovery Response messageindicates at least a dedicated discovery resource pool for the UE touse. Furthermore, the UE does not transmit the D2D Discovery ResourceRequest message to the WCN if a system information message indicatesthat dedicated discovery resources are not available. In step 1020, theUE receives a D2D Discovery Resource Response message from the WCN,wherein the D2D Discovery Resource Response message includes aconfiguration of dedicated discovery resource for the UE to use.

In one embodiment, a configuration of the common discovery resource pooland/or a configuration of the dedicated discovery resource pool areincluded in a system information message. In one embodiment, the UEwould read the configuration of the common discovery resource pool ifthe information included in the Discovery Response message indicates atleast a common discovery resource pool for the UE to use. In oneembodiment, the UE would read the configuration of the dedicateddiscovery resource pool if the information included in the DiscoveryResponse message indicates at least a dedicated discovery resource poolfor the UE to use.

In one embodiment, the UE transmits discovery signals using thededicated discovery resource based on the configuration. In addition,the UE monitors discovery signals in the discovery resource pool(s)indicated in the Discovery Response message based on configuration(s)read from a system information message. Also, the UE could be triggeredby an application in the UE to transmit the Discovery Request message.

Referring back to FIGS. 3 and 4, the device 300 includes a program code312 stored in memory 310 of a UE. The CPU 308 could execute program code312 to enable the UE (i) to transmit a Discovery Request message to theWCN, and (ii) to receive a Discovery Response message from the WCN,wherein the Discovery Response message includes information to indicateat least a discovery resource pool for the UE to use. In addition, theCPU 308 can execute the program code 312 to perform all of theabove-described actions and steps or others described herein.

In addition, the CPU 308 can execute the program code 312 to perform allof the above-described actions and steps or others described herein.

Various aspects of the disclosure have been described above. It shouldbe apparent that the teachings herein may be embodied in a wide varietyof forms and that any specific structure, function, or both beingdisclosed herein is merely representative. Based on the teachings hereinone skilled in the art should appreciate that an aspect disclosed hereinmay be implemented independently of any other aspects and that two ormore of these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. As an exampleof some of the above concepts, in some aspects concurrent channels maybe established based on pulse repetition frequencies. In some aspectsconcurrent channels may be established based on pulse position oroffsets. In some aspects concurrent channels may be established based ontime hopping sequences. In some aspects concurrent channels may beestablished based on pulse repetition frequencies, pulse positions oroffsets, and time hopping sequences.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, processors, means, circuits, and algorithmsteps described in connection with the aspects disclosed herein may beimplemented as electronic hardware (e.g., a digital implementation, ananalog implementation, or a combination of the two, which may bedesigned using source coding or some other technique), various forms ofprogram or design code incorporating instructions (which may be referredto herein, for convenience, as “software” or a “software module”), orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentdisclosure.

In addition, the various illustrative logical blocks, modules, andcircuits described in connection with the aspects disclosed herein maybe implemented within or performed by an integrated circuit (“IC”), anaccess terminal, or an access point. The IC may comprise a generalpurpose processor, a digital signal processor (DSP), an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, electrical components, opticalcomponents, mechanical components, or any combination thereof designedto perform the functions described herein, and may execute codes orinstructions that reside within the IC, outside of the IC, or both. Ageneral purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

It is understood that any specific order or hierarchy of steps in anydisclosed process is an example of a sample approach. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the processes may be rearranged while remaining within thescope of the present disclosure. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module (e.g., including executable instructions and relateddata) and other data may reside in a data memory such as RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM, or any other form of computer-readablestorage medium known in the art. A sample storage medium may be coupledto a machine such as, for example, a computer/processor (which may bereferred to herein, for convenience, as a “processor”) such theprocessor can read information (e.g., code) from and write informationto the storage medium. A sample storage medium may be integral to theprocessor. The processor and the storage medium may reside in an ASIC.The ASIC may reside in user equipment. In the alternative, the processorand the storage medium may reside as discrete components in userequipment. Moreover, in some aspects any suitable computer-programproduct may comprise a computer-readable medium comprising codesrelating to one or more of the aspects of the disclosure. In someaspects a computer program product may comprise packaging materials.

While the invention has been described in connection with variousaspects, it will be understood that the invention is capable of furthermodifications. This application is intended to cover any variations,uses or adaptation of the invention following, in general, theprinciples of the invention, and including such departures from thepresent disclosure as come within the known and customary practicewithin the art to which the invention pertains.

1. A method for allocating discovery resource pools, wherein at least acommon discovery resource pool and a dedicated discovery resource poolare supported for device-to-device (D2D) discovery in a wirelesscommunication network (WCN), comprising: the WCN receives a DiscoveryRequest message from a user equipment (UE); and the WCN transmits aDiscovery Response message to the UE, wherein the Discovery Responsemessage includes information to indicate at least a discovery resourcepool for the UE to use.
 2. The method of claim 1, wherein aconfiguration of the common discovery resource pool and a configurationof the dedicated discovery resource pool are included in a systeminformation message.
 3. The method of claim 1, wherein the DiscoveryRequest message includes at least a ProSe Application ID or at least apart or a subset of a ProSe Application ID.
 4. The method of claim 1,wherein the Discovery Response message further includes a ProSeApplication Code and/or a discovery filter.
 5. The method of claim 1,further comprising: the WCN receives a D2D Discovery Resource Requestmessage from the UE if the information indicates the dedicated discoveryresource pool for the UE to use.
 6. The method of claim 1, furthercomprising: the WCN transmits a D2D Discovery Resource Response messageto the UE, wherein the D2D Discovery Resource Response message includesa configuration of dedicated discovery resource for the UE to use. 7.The method of claim 1, further comprising: the WCN indicates ifdedicated discovery resources are available in a system informationmessage.
 8. A method for allocating discovery resource pools, wherein atleast a common discovery resource pool and a dedicated discoveryresource pool are supported for device-to-device (D2D) discovery in awireless communication network (WCN), comprising: a user equipment (UE)transmits a Discovery Request message to the WCN; and the UE receives aDiscovery Response message from the WCN, wherein the Discovery Responsemessage includes information to indicate at least a discovery resourcepool for the UE to use.
 9. The method of claim 8, wherein aconfiguration of the common discovery resource pool and a configurationof the dedicated discovery resource pool are included in a systeminformation message.
 10. The method of claim 8, further comprising: theUE reads a configuration of the common discovery resource pool if theinformation indicates the common discovery resource pool for the UE touse.
 11. The method of claim 8, further comprising: the UE reads from asystem information message a configuration(s) of the discovery resourcepool(s) indicated in the Discovery Response message.
 12. The method ofclaim 8, wherein the Discovery Request message includes at least a ProSeApplication ID or at least a part or a subset of a ProSe Application ID.13. The method of claim 12, wherein the ProSe Application ID is anidentity used for direct discovery and for identifying a service. 14.The method of claim 8, wherein the Discovery Response message furtherincludes a ProSe Application Code and/or a discovery filter.
 15. Themethod of claim 14, wherein the ProSe Application Code is contained in adiscovery signal transmitted “over the air” by the UE.
 16. The method ofclaim 8, further comprising: the UE transmits a D2D Discovery ResourceRequest message to the WCN if the information indicates the dedicateddiscovery resource pool for the UE to use.
 17. The method of claim 16,further comprising: the UE does not transmit the D2D Discovery ResourceRequest message to the WCN if a system information message indicatesthat dedicated discovery resources are not available.
 18. The method ofclaim 8, further comprising: the UE receives a D2D Discovery ResourceResponse message from the WCN, wherein the D2D Discovery ResourceResponse message includes a configuration of dedicated discoveryresource for the UE to use.
 19. The method of claim 18, furthercomprising: the UE transmits discovery signals using the dedicateddiscovery resource based on the configuration.
 20. The method of claim8, further comprising: the UE monitors discovery signals in thediscovery resource pool(s) indicated in the Discovery Response messagebased on a configuration(s) read from a system information message.